1. Field of the Invention
The present invention relates to an electric double layer capacitor apparatus that includes a control circuit for balancing charge voltage in each of a plurality of electric double layer capacitors connected in series.
2. Description of the Related Art
Various electric double layer capacitor apparatuses are known. An example of such apparatuses is disclosed in Japanese Utility Model Registration No. 2575358 entitled "Electric Double Layer Capacitor Apparatus".
The disclosed double layer capacitor apparatus includes a plurality of serially connected electric double layer capacitors. In order to balance charge voltage of each of the electric double layer capacitors, current control means comprising control transistors and a comparator is parallel-connected to each of the electric double layer capacitors. DC power supply for charging is connected between a positive terminal of a first electric double layer capacitor and a negative terminal of an end electric double layer capacitor. The interconnection between or wiring arrangement of the double layer capacitors is schematically shown in FIG. 12 hereof.
As shown in FIG. 12, the capacitor wiring arrangement 100 includes a plurality of serially connected electric double layer capacitors 101. Control circuit blocks 102 for charge voltage balancing are parallel-connected to each of the electric double layer capacitors 101. A charging DC power supply 103 is connected between a positive terminal 101a and a negative terminal 101b of the serially connected electric double layer capacitors 101. Consequently, harnesses 104 exist for connecting each of the electric double layer capacitors 101 and each of the control circuit blocks 102, thereby rendering the wiring arrangement 100 of the electric double layer capacitors complex and less reliable.